1. Field of the Invention
The present invention relates to the field of data storage systems such as disk drives. The invention particularly relates to a slider design for use in an optical or magneto-optical read-write head for high density recording and reading of information onto and from a storage medium.
2. Description of the Related Art
Data storage systems such as those used with computer systems, typically store data magnetically or magneto-optically onto a storage medium. Data stored on the medium, whether magnetic or optical, is contained in spiral or concentric tracks. An optical data storage system described in U.S. Pat. No. 4,799,210 to Wilson, includes a laser diode assembly mounted on a fixed platform, and an optical head mounted on a movable stage. The laser beam is coupled to the movable head through a flexible optical fiber.
Efforts to reduce the size and weight of optical heads are represented by optical integrated circuits or thin film structures. U.S. Pat. No. 4,911,512 to Yamamoto et al. describes a far-field type optical transducer, and a semi-conductor laser secured on a submount of silicon. A thin film silicon dioxide, SiO.sub.2, waveguide element and a glass waveguide layer are also fixed on the submount. A collimator lens, a beam splitter, and a focusing grating are formed on the glass waveguide layer.
Another attempt to achieve compactness and weight reduction of a magneto-optical head is described in U.S. Pat. No. 5,199,090 to Bell. The Bell patent describes a magneto-optic head fabricated on a glass slider and flown adjacent a magneto-optical disk. A transducer is fabricated on one end of the glass slider. A planar or channel waveguide structure, fabricated by ion exchange in the end face of the glass slider, couples light from a light source, such as a laser diode, to the disk for reading or writing.
Optical heads present several design, manufacturing, and operational concerns. One concern relates to the manufacturability of the slider, and particularly to the difficulty of forming the channels, grooves and air bearing surface on various sides of the slider. In addition, each of these channels and grooves has a predetermined tolerance, resulting in a very tight cumulative tolerance of the head.
Another concern is the complexity of handling, assembling, and aligning miniaturized optical and other components relative to each other, to the slider and to the disk storage medium. The assembly process of optical heads is generally complex and time consuming, and might not lend itself to mass production.
Yet another concern is the harsh environment in which these components operate, which might cause some of the components retained by an epoxy layer to become prematurely loose.
Still another concern is the retention of some of these components. For example, when an epoxy layer underlies a component and is disposed intermediate a hard surface and the component, the epoxy layer might not provide a fixed and adequate reference surface, as the component will be "floating" on the epoxy layer. As a result, an unacceptable tilt angle might be imparted to some of these components, which affects the working distance of the components relative to the data storage medium.